PURPOSE To investigate the effect of acid etchants with different low concentrations on remineralization of white spot lesion (WSL). METHODS WSL were prepared on buccal surfaces of 100 intact premolars using the methyl cellulose gel/lactic acid method. The samples were then placed in a remineralizing solution in addition to fluoride application twice daily for 5 minutes. The changes were quantified weekly using the Quantitative Light-induced Fluorescence (QLF) system. When changes in fluorescence radiance approached zero, each sample was etched with one of the following acids; 5% phosphoric acid, 10% phosphoric acid, 5% polyacrylic acid or 10% polyacrylic acid for 15 seconds, washed, dried, and placed again in the remineralizing solution. Two samples were randomly selected from each group for transverse microradiography (TMR) and scanning electron microscopy (SEM) analysis. RESULTS The 10% polyacrylic acid group showed the most significant improvement in fluorescence gain over the second phase of remineralization. It also showed partial loss of surface minerals without affecting enamel thickness as the phosphoric acid did. Additionally, 10% polyacrylic acid created the largest number of pores and smallest in size when compared to phosphoric acid, thus enhancing remineralization more efficiently than phosphoric acid without compromising the enamel outermost layer. CLINICAL SIGNIFICANCE The findings of this study may improve the remineralization of WSL from the bottom of the lesion instead of precipitation on the outermost layer of the lesion leaving a better quality of enamel. 10% polyacrylic acid enhanced remineralization more efficiently than phosphoric acid without compromising the enamel outermost layer. Copyright©American Journal of Dentistry.PURPOSE This randomized, controlled study evaluated the 2-year clinical performance of two flowable resin composites performed with a universal adhesive in two etching modes for restoring non-carious cervical lesions (NCCLs). METHODS One hundred NCCLs were restored with two flowable composites ( Charisma Opal Flow and G-aenial Universal Flo) and a universal adhesive (Single Bond Universal) with two etching modes (self-etch and etch&amp;rinse) in a random order. The restorations were evaluated for retention, marginal adaptation, anatomic form, marginal discoloration, surface texture and secondary caries (modified USPHS criteria) at baseline, and after 6, 12 and 24 months. RESULTS The clinical success for retention, surface texture and secondary caries parameters was scored as 100% for each group after 6, 12 and 24 months. The first acceptable changes (Bravo score) in marginal adaptation, anatomical form and marginal discoloration started to show up after 12 months for all test groups, except for etch&amp;rinse+Charisma Opal Flow. Self-etch+Charisma Opal Flow and self-etch+G-aenial Universal Flo showed progressive marginal discoloration that remained in the clinical acceptability level after 2 years. After 24 months, each resin composite restored with either the etch&amp;rinse mode or the self-etch mode of the universal adhesive showed similar clinical performance. Marginal discoloration was higher in the restorations performed with the self-etch system. Selective-etching can be favorable. CLINICAL SIGNIFICANCE The clinical performance of flowable composites performed with a universal adhesive in two etching modes was clinically acceptable after 24 months. Copyright©American Journal of Dentistry.PURPOSE To evaluate the effect of different contamination media and cleaning regimens on the adhesion of resin cement to lithium disilicate ceramic. METHODS Specimens (IPS e.max CAD) (n =15 per group) were etched with 5% hydrofluoric acid gel. While half of the specimens were silanized after etching, the other half was left etched only. After contamination with either saliva or dental stone, they were further divided into four subgroups depending on the cleaning regimens water rinsing only (WR), 80% ethanol (E), 37% phosphoric acid (PA), cleaning gel (CG). All specimens were re-silanized, coated with adhesive resin (Heliobond) and resin cement (Variolink II) was bonded. After thermocycling (5.000x, 5-55°C), ceramic-cement interface was loaded under shear (1 mm/minute) and failure types were classified. Data (MPa) were analyzed using 3-way ANOVA, Dunnett-T3 tests and Weibull moduli were calculated. RESULTS Saliva contamination (4.7±2.2-15.4±2.7) resulted in significantly lower bond strength compared to dental stone (17.8±4.8-23.6±2.7). Silanization before contamination showed protective effect especially for saliva (20.1±4.5-24.7±3.9) compared to non-silanized groups (4.7±2.2-15.4±2.7). Weibull modulus was the lowest for saliva-contaminated groups after cleaning with WR (2.22, 5.01) or E (1.14, 5.77) without and with initial silanization, respectively. Adhesive failures (272 out of 285) were commonly observed in all groups. Saliva contamination decreased the adhesion of luting cement to lithium disilicate ceramic considerably more than dental stone contamination, but silanization prior to try-in prevented deterioration in adhesion. CLINICAL SIGNIFICANCE Preliminary silanization of hydrofluoric acid etched lithium disilicate ceramic prior to saliva or dental stone contamination re-established resin luting cement adhesion, irrespective of the cleaning regimen used. Copyright©American Journal of Dentistry.PURPOSE To assess the association between obstructive sleep apnea (OSA) and enamel cracks. METHODS 219 patients were included. Separate operators assessed the sleep component of the study and the visual evaluation of the enamel cracks. Anthropometric data were also obtained. RESULTS Patients with slightly marked (superficial) enamel cracks had a significantly lower apnea-hypoapnea index (AHI) than the patients with moderately-to-severely marked (deep) craze lines. The frequency of patients with moderately-to-severely marked craze lines increased with the severity of OSA. https://www.selleckchem.com/products/U0126.html Spearman's correlation indicated the presence of a statistically significant association between the severity of enamel crack and the severity of OSA. Multiple regression analysis indicated that age, sex, body mass index and OSA significantly affected the enamel cracks. Compared to patients with slightly marked craze lines, those with moderate-to-severe craze lines are higher aged males, with a higher body mass index and increased severity of OSA.